JP2002316663A - Shock absorbing device of truck - Google Patents

Abstract

PROBLEM TO BE SOLVED: To absorb striking energy by a support shaft when an impact load acts on a cab and a cab mount bracket is rotated around the support shaft. SOLUTION: The cab mount bracket 17 is pivoted on a chassis frame 11 via the support shaft 22 and fixed on the frame 11 at a predetermined angle by a bolt 24. An end of the shaft 22 is fixed on the bracket 17 and the other end of the shaft 22 is fixed on the frame 11, and when the impact load acts on the bracket 17, the bolt 24 is sheared, and when the bracket 17 is rotated around the shaft 22 together with the end of the shaft 22, a torsional elastic force of the shaft 22 is resistance to the rotation of the bracket 17. The chassis frame comprises a section channel shaped side member 12 to which the bracket 17 is fixed, and a section channel shaped auxiliary member 26 fixed on the member 12 so as to form a closed section with the member 12 and to which the other end of the shaft 22 is fixed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for absorbing impact energy due to a truck collision or the like.

[0002]

2. Description of the Related Art Conventionally, as this kind of impact absorbing device, a truck having an energy absorbing member provided between a cab disposed on a chassis frame and the chassis frame has been disclosed (Japanese Patent Laid-Open No. 8-230724). ). On this track,
The front end of the energy absorbing member is opposed to the rear side of the tilt hinge member at a predetermined interval, and the rear end of the energy absorbing member is fixed to a stopper bracket fixed to the chassis frame. The cab is tiltably supported on the chassis frame by the tilt hinge member. In this truck, the entire cab moves rearward relative to the chassis frame when the truck collides. By causing the energy absorbing member to collide with the tilt hinge member along with this movement, the impact energy acting on the cab can be effectively absorbed, so that the crush amount of the cab in the collision can be reduced.

[0003]

SUMMARY OF THE INVENTION However, Japanese Patent Application Laid-Open No. Hei 8-2
In the truck disclosed in Japanese Patent No. 30724, the energy absorbing member absorbs the impact energy when the cab moves linearly under the impact load, that is, the energy absorbing member deforms linearly to absorb the impact energy. In addition, the size of the energy absorbing member increases, and a large space for mounting the energy absorbing member and the stopper bracket must be secured.
In addition, there is a problem that the structure becomes relatively complicated. SUMMARY OF THE INVENTION It is an object of the present invention to provide a truck impact absorbing device capable of effectively absorbing impact energy with a relatively small and simple structure.

[0004]

The invention according to claim 1 is
As shown in FIG. 1, this is an improvement of a truck having a cab mount bracket 17 pivotally supported on a chassis frame 11 via a support shaft 22 and fixed at a predetermined angle to the chassis frame 11 by bolts 24 or caulking pins. . The characteristic configuration is that one end of the support shaft 22 is fixed to the cab mount bracket 17, the other end of the support shaft 22 is fixed to the chassis frame 11, and the bolt 24 or the caulking is applied when the cab mount bracket 17 receives an impact load. The pins are sheared and the cab mount bracket 17 is mounted on the chassis frame 1.
1, the torsion elastic force of the support shaft 22 becomes a resistance to the rotation of the cab mount bracket 17 when the support shaft 22 rotates together with one end of the support shaft 22 around the support shaft 22.

In the shock absorbing device according to the first aspect, when the cab 13 receives an impact load, the cab 13 tends to move relative to the chassis frame 11, so that the cab mount bracket 17 is mounted on the chassis frame. 1
The cab mount bracket 17 starts to rotate about the support shaft 22 when the bolt 24 or the caulking pin attached to 1 is sheared. At this time, the torsional elastic force of the support shaft 22 becomes a resistance to the rotation of the cab mount bracket 17, and the impact energy generated by the impact load is transferred to the bolt 24.
Etc. and the torsional elastic force of the support shaft 22 can be efficiently absorbed. If all of the impact energy can be absorbed by the shearing force of the bolt 24 and the torsional elastic force of the support shaft 22, the chassis frame 11 will not be deformed or damaged.

According to a second aspect of the present invention, in the first aspect of the present invention, the chassis frame 11 has a channel-shaped side member 12 to which a cab mount bracket 17 is fixed, and a closed cross section with the side member 12. An impact absorbing device for a truck comprising an auxiliary member 26 having a channel-shaped cross-section, which is fixed to the side member 12 and the other end of the support shaft 22 is fixed. In the shock absorbing device according to the second aspect, it is possible to obtain a shock absorbing device that absorbs impact energy with a simple structure in which the auxiliary member 26 is provided on the side member 12 existing in the conventional truck.

[0007]

Embodiments of the present invention will now be described with reference to the drawings. As shown in FIG. 3, the chassis frame 11 of the cab-over type truck 10 includes a pair of side members 12 having a channel-like cross section and extending in the traveling direction of the truck 10. A cab 13 is provided. The cab 13 includes a cab body 15 and a floor panel 14 of the cab body 15.
A pair of floor members 16 are provided on the lower surface of the vehicle 10 in the traveling direction of the truck 10 and provided opposite to the pair of side members 12. Since the pair of side members 12 and the pair of floor members 16 are bilaterally symmetric, the left side member 12 and the like will be described below, and the description of the right side member and the like will be omitted. Floor member 16
A receiving member 19 is fixed to the lower surface near the front end of the cab mount bracket 17. The receiving member 19 is connected to an upper end of the cab mount bracket 17 via a connecting pin 21. Attached to
The receiving member 19, the connecting pin 21 and the bracket 17 are components of the cab 13. The front end of the cab main body 15 is rotatably held by the connection pin 21, that is, the cab main body 15 is configured to be tiltable around the connection pin 21.

As shown in FIGS. 1 and 2, the bracket 1
The lower end of 7 is pivotally supported by the side member 12 via the support shaft 22. At the lower end of the bracket 17, a first through hole 17a (FIG. 1) through which the support shaft 22 can be inserted is formed.
A second through-hole 12a (FIG. 1) into which the support shaft 22 can be loosely inserted is formed on the side surface of the. A first boss 23 is fixed to one surface of the lower end of the bracket 17, and a third through hole 23a (FIG. 1) through which the support shaft 22 can be inserted is formed in the first boss 23. On the inner peripheral surfaces of the first and third through holes 17a and 23a, a large number of fine mountain-shaped internal teeth are formed at equal intervals, and on the outer peripheral surface of the support shaft 22, the first and third through holes 17a and 23a are formed. A large number of external teeth that can mesh with a large number of internal teeth are formed. Support shaft 22
Is configured to be rotatable with respect to the side member 12, and the bracket 17 is serrated and connected to one end of the support shaft 22 together with the first boss 23, that is, the bracket 17 is
Is fixed to one end so that it cannot rotate. The lower end of the bracket 17 is fixed to the outer surface of the side member 12 with four bolts 24 and four nuts 25 in a state where the bracket 17 is oriented at a predetermined angle, in this embodiment, the bracket 17 is vertically upward. (FIG. 1).

On the other hand, on the side member 12 to which the bracket 17 is fixed, an auxiliary member 26 having a channel-shaped cross section which forms a closed cross section with the side member 12 is provided.
7 is fixed to the side member 12 so as to face the side member 7. A fourth through hole 26a (FIG. 1) through which the support shaft 22 can be inserted is formed in a portion of the auxiliary member 26 facing the bracket 17, and a large number of support shafts 22 are formed in the inner peripheral surface of the fourth through hole 26a. A large number of internal teeth that can mesh with the external teeth are formed. A second surface is formed on one surface of the auxiliary member 26 in which the fourth through hole 26a is formed.
The boss 27 is fixed, and a fifth through hole 27a (FIG. 1) through which the support shaft 22 can be inserted is formed in the second boss 27. A large number of fine mountain-shaped internal teeth are also formed at equal intervals on the inner peripheral surface of the fifth through hole 27a, and the second boss 27 and the auxiliary member 26 are serrated and connected to the other end of the support shaft 22. The other end is non-rotatably fixed to the chassis frame 11 including the auxiliary member 26.

As shown in FIG. 1, the support shaft 22 is penetrated through first to fifth through holes 23a, 27a, 12a, 26a, 27a, and in this state, retaining rings 34 and 35 for C-shaped shafts for preventing the shaft 22 from coming off. Are fitted to both ends of the support shaft 22. Then, with the retaining rings 34 and 35 fitted, one end of the support shaft 22 is fixed to the cab mount bracket 17, and the other end of the support shaft 22 is fixed to the chassis frame 11. Therefore, the width dimension in FIG. 1 of the closed cross section formed by the auxiliary member 26 together with the side member 12 is the length L that can be twisted between the fixed one end of the support shaft 22 and the fixed other end. here,
When the support shaft 22 is made of spring steel capable of absorbing and storing energy by torsion, the diameter of the torsionable portion is D.
Then, the relationship between D and L is determined by satisfying the following requirements.

That is, the support shaft 22 is required to be able to absorb impact energy by being twisted. Here, spindle 2
2 is G, the shear stress is τ, the torque related to the support shaft is T, the torsion angle of the support shaft 22 is σ, and the energy absorbed by the support shaft 22 is E. Support shaft 2
The relationship between T and σ in 2 is represented by T = (πGD ⁴ / 32L) × σ (Equation 1-1). Relationship torque T and twist angle σ from equation 1-1 is in a linear relationship as shown in FIG. 7, the slope (πGD ^4/32
L) and the area surrounded by the horizontal axis (torsion angle σ) represents the energy absorption E. Therefore, the relationship between the energy absorption amount E and the twist angle σ is E = (＝) × (πGD ⁴ / 32L) × σ ² = (ΠGD ⁴ / 64L) × σ ² (Formula 1-2) From the above equation 1-2, the relationship between D and L in the support shaft 22 for absorbing the impact energy by twisting the support shaft 22 is as follows: D ⁴ / L ≧ (64E / πGσ ² ) (Equation 1) 3)

On the other hand, the support shaft 22 is required not only to absorb impact energy but also not to be sheared and broken at a predetermined torsion angle. Here, the torsion angle σ and the shear stress τ in the support shaft 22
Is given by τ = (GD / 2L) σ (Equation 2)
1) is expressed as From equation (2-1), in order to prevent the support shaft 22 from shearing and breaking at a predetermined torsion angle, the allowable maximum shear stress must be τ.
where τmax ≧ (GD / 2L) σ (2)
-2). Accordingly, the relationship between D and L at which the support shaft 22 does not break at a predetermined torsion angle is: (2τmax / Gσ) ≧ (D / L) (Equation 2-3)
Becomes That is, the relationship between the torsional length L of the support shaft 22 and the diameter D at that portion is expressed by the above-described formulas 1-3 and 2
-3 is satisfied.

Returning to FIG. 3, a rear arch 36 is provided on a portion of the pair of side members 12 facing the rear end of the cab body 15, and a cushion member 37 formed of rubber or the like is provided on the rear arch 36. (FIG. 3). A cab lock device 38 is provided between the rear arch 36 and the back of the cab body 15. When the lock device 38 is locked, the cab body 15 cannot be tilted up, and when the lock device 38 is released, the cab body 15 can be tilted up.

In the shock absorbing device configured as described above,
When the front surface of the cab body 15 of the truck 10 receives an impact load F (FIGS. 2 and 3) when the truck 10 collides with the rear end of the bed of another truck (not shown), the receiver 19 is moved to the cab body 15 and the floor. An attempt is made to move rearward with the member 16 relative to the side member 12 of the chassis frame 11. For this reason, the four bolts 24 attaching the lower end of the bracket 17 to the side member 12 are sheared by the impact load, and the bracket 17 is moved rearward around the support shaft 22 (in the direction indicated by the one-dot chain line arrow in FIG. 2). Start to rotate. When the bracket 17 rotates, the bracket 17
One end of the support shaft 22 fixed to the
Rotates with. On the other hand, since the other end of the support shaft 22 is fixed to the auxiliary member 26 which is the chassis frame 11, the twistable range L between the one end fixed to the bracket 17 and the other end fixed to the auxiliary member 26 is set. The support shaft 22 is twisted and absorbs and stores energy. That is, the impact energy generated when the front surface of the cab 13 receives the impact load F can be efficiently absorbed by the elastic force based on the shearing of the bolt 24 and the torsional deformation of the support shaft 22.

Further, all of the above impact energy is
If it can be absorbed by the shearing force of 4 and the torsional elastic force of the support shaft 22, the side member 12 will not be deformed or damaged. Therefore, the chassis frame 11 which is provided over the entire length of the truck 10 and requires much repair time
Since it is not necessary to replace the device, repair time and cost can be reduced.

In the above embodiment, the auxiliary member 26
The other end of the support shaft 22 is directly serrated and connected to the support member 26 so that the width dimension in the closed section formed by the auxiliary member 26 together with the side member 12 is directly equal to the length L to which the support shaft 22 can be twisted. In the case where a relatively long closed section space is required in relation to the diameter of the shaft, as shown in FIG.
b, and a flange portion 27c continuously formed at the base end of the body portion 27b is fixed to the auxiliary member 26, and the body portion 27b is fixed.
The fifth through-hole 27a in which the other end of the support shaft 22 is fixed to the tip of c
May be formed. Second boss 2 having this body 27b
In 7, the width of the closed section formed by the auxiliary member 26 together with the side member 12 can be reduced, and if the second boss 27 itself is made of spring steel, the body 27b of the second boss 27 is also twisted. Energy can be absorbed and stored.

In the above embodiment, the first through fifth through holes 23a, 17a, 12
a, 26a, and 27a, and in this state, C-shaft retaining rings 34 and 35 for preventing slipping were fitted to both ends. As shown in FIG. If it can absorb and accumulate, the support shaft 22
May be formed with a mounting flange 22b at one end. Even if such a support shaft 22 is used,
The impact energy generated when the front surface of the cab 13 receives the impact load F can be efficiently absorbed by the elastic force based on the torsional deformation of the support shaft. In the above embodiment, the straight support shaft 22 is used. However, in the case where the diameter of the support shaft 22 can be made relatively small in relation to the length L to which the support shaft 22 can be twisted, FIG. As shown, the diameter of the intermediate portion of the support shaft 22 is reduced, and the length thereof is
The length L that can be twisted may be 2.

In the above embodiment, the bracket 1
Although the lower end of the bracket 7 is fixed to the side surface of the side member 12 by the bolt 24, the lower end of the bracket 17 may be fixed to the side surface of the side member 12 by a caulking pin. Further, in the above embodiment, the upper end of the bracket and the receiving member are connected by the connecting pin. However, the upper end of the bracket and the receiving member are connected by a cab floating mechanism, that is, a link mechanism such as a link lever and an air spring or a coil spring. You may connect by the mechanism which has. Further, in the above embodiment, one end of the support shaft 22 and the bracket 17 are serrated and connected, and
Of the support shaft 22 and the bracket 17 may be spline-coupled, and the other end of the support shaft 22 and the auxiliary member 26 may be spline-coupled.

[0019]

As described above, according to the present invention, the cab mount bracket is pivotally supported on the chassis frame via the support shaft, and the cab mount bracket is fixed to the chassis frame by bolts or caulking pins. Since one end of the shaft is fixed to the cab mount bracket and the other end of the support shaft is fixed to the chassis frame, when the cab receives an impact load, the cab tries to move relative to the chassis frame. Bolts or caulking pins attaching the bracket to the chassis frame shear and the cab mount bracket begins to rotate about the pivot. At this time, the torsional elastic force of the support shaft serves as a resistance to the rotation of the cab mount bracket, so that the impact energy generated by the impact load can be efficiently absorbed by the shearing of the bolts and the torsional elastic force of the support shaft. Further, if all of the above impact energy can be absorbed by the shearing force of the bolt and the torsional elastic force of the support shaft, the chassis frame will not be deformed or damaged, so it is provided over the entire length of the truck and requires a lot of repair time. It is not necessary to replace the chassis frame, and the repair time and cost can be reduced.

[Brief description of the drawings]

FIG. 1B shows a shock absorbing device according to an embodiment of the present invention.
-B line sectional drawing.

FIG. 2 is an enlarged sectional view of a portion A in FIG. 3;

FIG. 3 is a longitudinal sectional view of a cab of a truck on which the shock absorbing device is mounted.

FIG. 4 is a cross-sectional view corresponding to FIG. 1, illustrating the shock absorbing device having a body portion formed on a second boss.

FIG. 5 is a cross-sectional view corresponding to FIG. 1, illustrating the shock absorbing device in which a flange is formed on a support shaft.

FIG. 6 is a cross-sectional view corresponding to FIG. 1, illustrating a shock absorbing device in which a small diameter portion is formed on a support shaft.

FIG. 7 is a diagram showing a linear relationship between a torque T and a torsion angle σ on a support shaft.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Track 11 Chassis frame 12 Side member 17 Cab mount bracket 22 Support shaft 24 Bolt 26 Auxiliary member L Twistable length of support shaft D Diameter at twistable portion

Claims (2)

[Claims] A cab mount bracket (17) pivotally supported on a chassis frame (11) via a support shaft (22) and fixed at a predetermined angle to the chassis frame (11) by bolts (24) or caulking pins. ), One end of the support shaft (22) is connected to the cab mount bracket (1).
7), the other end of the support shaft (22) is fixed to the chassis frame (11), and when the cab mount bracket (17) receives an impact load, the bolt (24) or the caulking pin Is sheared and the cab mount bracket (17) is
(11) The torsional elastic force of the support shaft (22) when rotated together with one end of the support shaft (22) about the support shaft (22) with respect to the rotation resistance of the cab mount bracket (17). An impact absorbing device for a truck, wherein the impact absorbing device is configured to: 2. A chassis frame (11) comprising a channel-shaped side member (12) to which a cab mount bracket (17) is fixed, and said side member (12) forming a closed cross section with said side member (12). (22) fixed to (12) and supporting shaft (22)
2. The truck impact absorbing device according to claim 1, further comprising an auxiliary member having a channel-like cross section to which the other end is fixed.